Anesthesia plays a crucial role in regulating physiological states during medical procedures,but its effects on neural activity remain incompletely understood,particularly at the prefrontal cortical level.The prefront...Anesthesia plays a crucial role in regulating physiological states during medical procedures,but its effects on neural activity remain incompletely understood,particularly at the prefrontal cortical level.The prefrontal cortex is essential for various cognitive and motor functions,yet high-spatiotemporal-resolution electrodes at the cellular level remain challenging to develop,which has hindered the acquisition of detailed electrophysiological data from anesthetized subjects.Here,we design a 16-channel silicon-based microelectrode array(MEA),which,after modification with platinum black nanoparticles,exhibits significantly reduced impedance(22.5 kΩ)and increased phase(−33.5°),enhancing its electrical performance and electrophysiological signal detection capabilities.Using this modified MEA,we have recorded cellular-level neural activity during the recovery process of a rhesus macaque following prolonged anesthesia.Over a 660 s period,we observed a gradual increase in the neuronal firing rate in the F7 area,along with distinctive patterns in local field potentials across different frequency bands.Notably,power in the δ and θ bands increased continuously during recovery,highlighting their potential role in the transition from anesthesia to wakefulness.Our findings provide new insights into the dynamic recovery process of cortical neurons and offer a powerful tool for high-spatiotemporal-resolution neural monitoring in nonhuman primates.展开更多
The development of bifunctional electrocatalysts for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)at high current density under industrial temperatures is crucial for large-scale industrial hydrog...The development of bifunctional electrocatalysts for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)at high current density under industrial temperatures is crucial for large-scale industrial hydrogen production from water splitting.In this work,M-MnO_(2)@TNTA composite electrodes were prepared by depositing various metal ion-doped manganese oxide nanoparticles on the titania nanotube array(TNTA)by successive ionic layer adsorption reaction(SILAR)method,and their HER and OER electrocatalytic performances were investigated in 1 M KOH.Results show that the CoFe-MnO_(2)@TNTA composite electrode prepared by simultaneous doping of Co^(3+)and Fe^(3+)in MnO_(2) exhibits optimal catalytic performance.Compared with MnO_(2)@TNTA without ion doping,the overpotentials of CoFe-MnO_(2)@TNTA at 10 mA cm^(-2)(η_(10))for HER and OER are reduced by 571 and 665 mV.In addition,the electrode perfor-mance can be significantly enhanced by increasing the test temperature,and the porous array structure enables CoFe-MnO_(2)@TNTA to exhibit better performance at high current densities.At 50℃,which is the common industrial electrolytic water temperature,the η_(10) of CoFe-MnO_(2)@TNTA for HER is almost equal to that of the Pt/C electrode.The η_(100) of CoFe-MnO_(2)@TNTA for HER is reduced by 35 mV compared with the Pt/C electrode.Moreover,η_(200) of CoFe-MnO_(2)@TNTA for OER is significantly lowered by 111 and 184 mV compared with IrO_(2) and RuO_(2) electrodes.Utilizing CoFe-MnO_(2)@TNTA as both the cathode and anode for overall water splitting,the electrolysis voltage is merely 2.33 V under the current density of 200 mA cm^(-2),much lower than that of IrO_(2)(+)||Pt/C(-)(2.68 V).The present work may provide a valuable reference for the development of self-supporting bifunctional electrodes suitable for high-current-density water splitting at industrial temperatures.展开更多
Developing effective,versatile,and high-precision sensing interfaces remains a crucial challenge in human-machine-environment interaction applications.Despite progress in interaction-oriented sensing skins,limitations...Developing effective,versatile,and high-precision sensing interfaces remains a crucial challenge in human-machine-environment interaction applications.Despite progress in interaction-oriented sensing skins,limitations remain in unit-level reconfiguration,multiaxial force and motion sensing,and robust operation across dynamically changing or irregular surfaces.Herein,we develop a reconfigurable omnidirectional triboelectric whisker sensor array(RO-TWSA)comprising multiple sensing units that integrate a triboelectric whisker structure(TWS)with an untethered hydro-sealing vacuum sucker(UHSVS),enabling reversibly portable deployment and omnidirectional perception across diverse surfaces.Using a simple dual-triangular electrode layout paired with MXene/silicone nanocomposite dielectric layer,the sensor unit achieves precise omnidirectional force and motion sensing with a detection threshold as low as 0.024 N and an angular resolution of 5°,while the UHSVS provides reliable and reversible multi-surface anchoring for the sensor units by involving a newly designed hydrogel combining high mechanical robustness and superior water absorption.Extensive experiments demonstrate the effectiveness of RO-TWSA across various interactive scenarios,including teleoperation,tactile diagnostics,and robotic autonomous exploration.Overall,RO-TWSA presents a versatile and high-resolution tactile interface,offering new avenues for intelligent perception and interaction in complex real-world environments.展开更多
In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved cerami...In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved ceramic substrate,and laser sintering and microdroplet spraying processes are used to add the conductive metal on the curved substrate.The problems of gain loss,bandwidth reduction,and frequency shift caused by high temperatures are addressed by using a proper antenna design,with parasitic patches,slots,and metal resonant cavities.The antenna prototype is characterized by the curved substrates and the conductive metals for the power dividers,the patch,and the ground plane;its performance is examined up to a temperature of 600℃in a muffle furnace and compared with the results from the numerical analysis.The results show that the antenna can effectively function at 600℃and even higher temperatures.展开更多
To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as wel...To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.展开更多
Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-...Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.展开更多
A microelectrode array（MEA） is presented, which is composed of 60 independent electrodes with 59 working ones and one reference one, and they are divided into 30 pairs. Except for the reference electrode, each pair ...A microelectrode array（MEA） is presented, which is composed of 60 independent electrodes with 59 working ones and one reference one, and they are divided into 30 pairs. Except for the reference electrode, each pair consists of one stimulating electrode and one recording electrode. Supported by the peripheral circuits, four electrode states to study the bioelectrical signal of biological tissue or slice cultured in-vitro on the surface of the electrodes can be realized through each pair of electrodes. The four electrode states are stimulation, recording, stimulation and recording simultaneously, and isolation. The state of each pair of working electrodes can be arbitrarily controlled according to actual needs. The MEAs are fabricated in printed circuit board （PCB） technology. The total area of the PCB-based MEA is 49 mm × 49 mm. The impedance measurement of MEA is carried out in 0.9% sodium chloride solution at room temperature by means of 2-point measurements with an Agilent LCR meter, and the test signal for the impedance measurement is sinusoidal （AC voltage 50 mV, sweeping frequency 20 Hz to 10 kHz）. The electrode impedance is between 200 and 3 kΩ while the frequency is between 500 and 1 000 Hz. The electrode impedance magnitude is inversely proportional to the frequency. Experiments of toad sciatic nerve in-vitro stimulation and recording and signal regeneration between isolated toad sciatic nerves are carried out on the PCB-based MEA. The results show that the MEA can be used for bioelectrical signal stimulation, recording, stimulation and recording simultaneously, and isolation of biological tissues or slices in-vitro.展开更多
Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the p...Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.展开更多
Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose c...Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose cell-electrode interface.To investigate intracellular electrophysiological signals with high sensitivity,electroporation was used to obtain intracellular recordings.In this study,a biosensing system based on a nanoporous electrode array(NPEA)integrating electrical perforation and signal acquisition was established to dynamically and sensitively record the intracellular potential of cardiomyocytes over a long period of time.Moreover,nanoporous electrodes can induce the protrusion of cell membranes and enhance cell-electrode interfacial coupling,thereby facilitating effective electroporation.Electrophysiological signals over the entire recording process can be quantitatively and segmentally analyzed according to the signal changes,which can equivalently reflect the dynamic evolution of the electroporated cardiomyocyte membrane.We believe that the low-cost and high-performance nanoporous biosensing platform suggested in this study can dynamically record intracellular action potential,evaluate cardiomyocyte electroporation,and provide a new strategy for investigating cardiology pharmacological science.展开更多
Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applicatio...Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications.Existing schemes are limited by flexibility,biosafety,and manufacturing costs,which create large barriers for wider applications.Here,we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface,robustness of microneedles to penetrate the skin without fracture,and a simplified process to allow mass production.The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording.The normalized electrode–skin contact impedance reaches 0.98 kΩcm^(2)at 1 kHz and 1.50 kΩcm^(2)at 10 Hz,a record low value compared to previous reports and approximately 1/250 of the standard electrodes.The morphology,biosafety,and electrical/mechanical properties are fully characterized,and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized.The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording(over 8 h per night),providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.展开更多
Conducting polymers have been studied extensively. An interesting property of the conducting polymer is that the conductivity of some polymers, such as polypyrrolc, polyaniline, poly(3-methylthiophene) etc. , is affec...Conducting polymers have been studied extensively. An interesting property of the conducting polymer is that the conductivity of some polymers, such as polypyrrolc, polyaniline, poly(3-methylthiophene) etc. , is affected by the voltage applied to them. For polypyrrole, the oxidized state is an electronic conductor and the reduced state is essentially insulating. Using this property, one can fabricate the polymer-based electronic devices. Experimental results of Pickun展开更多
Plasma Synthetic Jet(PSJ) actuators have shown wide and promising application prospects in high-speed flow control, due to their advantages including high exhaust speed, wide frequency band, rapid response, and non-mo...Plasma Synthetic Jet(PSJ) actuators have shown wide and promising application prospects in high-speed flow control, due to their advantages including high exhaust speed, wide frequency band, rapid response, and non-moving components. Although previous studies on PSJ actuators are abundant, most of them have focused on the performance of a single actuator. However, in practice, an actuator array is very necessary for large-scale aerodynamic actuation on account of the small affected area of a single PSJ. In this paper, the characteristics of a twoelectrode plasma synthetic jet actuator array in serial are investigated experimentally. Compared to a parallel actuator array, the serial actuator array requires simpler power supply design and is much easier to realize. High-speed photography of the discharge evolution, voltage-current measurement, and shadowgraphy visualization are used in the investigation. Experimental results show that, for the serial actuator array, weak discharges happen firstly between energized and suspending electrodes, and then a strong pulse arc discharge is triggered. The breakdown voltage in serial is irrelevant to such factors as the number of actuators, the maximum or minimum gap in serial,the connection sequence, etc. It is mainly determined by the sum of gaps. For serial actuators with the same anode-to-cathode spacing, the energy deposition is the same, and the jet is synchronous and similar. Because of the entrainment and merging of adjacent jet vortices, the jet front speed of an aligned synchronous jet array increases as the orifice distance decreases. To achieve the highest jet front velocity, the orifice of the actuator has an optimal diameter.展开更多
Objective: Determine the occurrence rate of cochlear implant (CI) electrode tip fold-over and electrode scalar deviation as reported in patient cases with different commercial electrode types. Data-sources: PubMed sea...Objective: Determine the occurrence rate of cochlear implant (CI) electrode tip fold-over and electrode scalar deviation as reported in patient cases with different commercial electrode types. Data-sources: PubMed search for identifying peer-reviewed articles published till 2018 on CI electrode tip fold-over and scalar deviation. Key-words for searching were “Cochlear electrode tip fold-over”,“Cochlear electrode scalar position” and “Cochlear electrode scalar location”. Articles-selection: Only if electrode related issues were investigated in patient cases. 38 articles met the inclusion-criteria. Results: 13 articles on electrode tip fold-over issue covering 3177 implanted ears, out of which 50 ears were identified with electrode tip fold-over with an occurrence rate of 1.57%. Out of 50 ears, 43 were implanted with pre-curved electrodes and the remaining 7 with lateral-wall electrodes. One article reported on both tip fold-over and scalar deviation. 26 articles reported on the electrode scalar deviation covering an overall number of 2046 ears out of which, 458 were identified with electrode scalar deviation at a rate of 22.38%. After removing the studies that did not report on the number of electrodes per electrode type, it was 1324 ears implanted with pre-curved electrode and 507 ears with lateral-wall electrode. Out of 1324 pre-curved electrode implanted ears, 424 were reported with scalar deviation making an occurrence rate of 32%. Out of 507 lateral-wall electrode implanted ears, 43 were associated with scalar deviation at an occurrence rate of 6.7%. Conclusion: This literature review revealing the fact of higher rate of electrode insertion trauma associated with pre-curved electrode type irrespective of CI brand is one step closer to obsolete it from the clinical practice in the interest of patient's cochlear health.展开更多
Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stab...Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stability have hindered their large-scale commercial application.Herein,aflexible capacitive pressure sensor based on an interdigital electrode structure with two porous microneedle arrays(MNAs)is pro-posed.The porous substrate that constitutes the MNA is a mixed product of polydimethylsiloxane and NaHCO3.Due to its porous and interdigital structure,the maximum sensitivity(0.07 kPa-1)of a porous MNA-based pressure sensor was found to be seven times higher than that of an imporous MNA pressure sensor,and it was much greater than that of aflat pressure sensor without a porous MNA structure.Finite-element analysis showed that the interdigital MNA structure can greatly increase the strain and improve the sensitivity of the sen-sor.In addition,the porous MNA-based pressure sensor was found to have good stability over 1500 loading cycles as a result of its bilayer parylene-enhanced conductive electrode structure.Most importantly,it was found that the sensor could accurately monitor the motion of afinger,wrist joint,arm,face,abdomen,eye,and Adam’s apple.Furthermore,preliminary semantic recognition was achieved by monitoring the movement of the Adam’s apple.Finally,multiple pressure sensors were integrated into a 33 array to detect a spatial pressure distribu-×tion.Compared to the sensors reported in previous works,the interdigital electrode structure presented in this work improves sensitivity and stability by modifying the electrode layer rather than the dielectric layer.展开更多
A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffracti...A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.展开更多
Oxygen electrocatalysis,exemplified by the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is central to energy storage and conversion technologies such as fuel cells,metal-air batteries,and water ele...Oxygen electrocatalysis,exemplified by the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is central to energy storage and conversion technologies such as fuel cells,metal-air batteries,and water electrolysis.However,highly effective and inexpensive earth-abundant materials are sought after to replace the noble metal-based electrocatalysts currently in use.Recently,metal-organic frameworks(MOFs)and carbon-based MOF derivatives have attracted considerable attention as efficient catalysts due to their exceedingly tunable morphologies,structures,compositions,and functionalization.Here,we report two-dimensional(2D)MOF/MOF derivative coupled arrays on nickel foam as binder-free bifunctional ORR/OER catalysts with enhanced electrocatalytic activity and stability.Their remarkable electrochemical properties are primarily attributed to fully exposed active sites and facilitated charge-transfer kinetics.The coupled and hierarchical nanosheet arrays produced via our growth-pyrolysis-regrowth strategy offer promise in the development of highly active electrodes for energy-related electrochemical devices.展开更多
Direct electrochemical reduction of CO2 to multicarbon products is highly desirable, yet challenging. Here, we present a potentiostatic pulse-electrodeposition of high-aspect-ratio CuxAuy nanowire arrays (NWAs) as hig...Direct electrochemical reduction of CO2 to multicarbon products is highly desirable, yet challenging. Here, we present a potentiostatic pulse-electrodeposition of high-aspect-ratio CuxAuy nanowire arrays (NWAs) as high-performance electrocatalysts for the CO2 reduction reaction (CO2RR). The surface electronic structure related to the Cu:Au ratio in the CuxAuy NWAs could be facilely modulated by controlling the electrodeposition potential and the as-fabricated CuxAuy NWAs could be directly used as the catalytic electrode for the CO2RR. The morphology of the high-aspect-ratio nanowire array significantly lowers the onset potential of the alcohol formation due to the diffusion-induced enhancement of the local pH and CO concentration near the nanowire surface. Besides, the properly adjusted surface electronic structure of the CuxAuy NWA enables the adsorption of CO and facilitates the subsequent CO reduction to ethanol via the C-C coupling pathway. Owing to the synergistic effect of morphology and electronic structure, the optimized CuxAuy NWA selectively reduces CO2 to ethanol at low potentials of -0.5——0.7 V vs. RHE with a highest Faradaic efficiency of 48%. This work demonstrates the feasibility to optimize the activity and selectivity of the Cu-based electrocatalysts toward multicarbon alcohols for the CO2RR via simultaneous adjustment of the electronic structure and morphology of the catalysts.展开更多
Neuronal connections can be detected by neuronal network discharges in hippocampal neurons cultured on multi-electrodes.However,the multi-electrode-array（MEA）has not been widely used in hippocampal slice culture stu...Neuronal connections can be detected by neuronal network discharges in hippocampal neurons cultured on multi-electrodes.However,the multi-electrode-array（MEA）has not been widely used in hippocampal slice culture studies focused on epilepsy.The present study induced spontaneous synchronous epileptiform activity using low Mg2＋artificial cerebrospinal fluid on acute hippocampal slices to record hippocampal discharges with MEA.Results showed that burst duration and average number of spikes in a burst were significantly greater in the CA3 compared with dentate gyrus and CA1 areas.In Schaffer cut-off group,CA1 area discharges disappeared,but synchronous discharges remained in the CA3 area.Moreover,synchronous discharge frequency in the Schaffer cut-off group was similar to control.However,burst duration and average number of spikes in a burst were significantly decreased compared with control（P 〈 0.05）.Results demonstrated that highest neuronal excitability occurred in the CA3 area,and synchronous discharges induced by low Mg2＋originated from the CA3 region.展开更多
The advancement of supe rcapacitors largely relies on the innovation of electrode materials with high-rate performance and ultra-long cycling stability.In this work,unique N-doped nanofibers on carbon cloth(NCNFs/CC) ...The advancement of supe rcapacitors largely relies on the innovation of electrode materials with high-rate performance and ultra-long cycling stability.In this work,unique N-doped nanofibers on carbon cloth(NCNFs/CC) are prepared by an electrodepositio n-annealing method for application in supercapacitors.The as-prepared N-doped nanofibers(N-CNFs) show diameters of 100-150 nm and cross-link with each other fo rming porous conductive network.Due to enhanced conductivity and reinforced structural stability,the N-CNFs/CC arrays are demonstrated with better electrochemical performance than CNFs/CC counterpart,including higher specific capacitance(195.2 F g^-1 at a current density of 2.5 A g^-1),excellent rate capability(80.5.% capacity retention as the rate increases from 2.5-20 A g^-1) and good cycling stability(99.5.%retention after 10,000 cycles).These reinforced electrochemical properties are attributed to N-doped conductive architecture with faster ion/electron transfer paths and more active sites.Our findings may offe r a new way for construction of advanced high-rate electrodes for energy storage.展开更多
Copper and titanium remain relatively plentiful in earth crust.Therefore,using them in solar energy conversion technologies are of significant interest.In this work,cuprous oxide（Cu2O）-modified short TiO2 nanotube a...Copper and titanium remain relatively plentiful in earth crust.Therefore,using them in solar energy conversion technologies are of significant interest.In this work,cuprous oxide（Cu2O）-modified short TiO2 nanotube array electrode was prepared based on the following two design ideas:first,the short titania nanotubes obtained from sonoelectrochemical anodization possess excellent charge separation and transportation properties as well as desirable mechanical stability;second,the sonoelectrochemical deposition technique favours the improvement in the combination between Cu2O and TiO2 nanotubes,and favours the dispersion of Cu2O particles.UV-Vis absorption and photo-electronchemical measurements proved that the Cu2O coating extended the visible spectrum absorption and the solar spectrum-induced photocurrent response.Under AM1.5 irradiation,the photocurrent density of the composite electrode（i.e.sonoelectrochemical deposition for 5 min） was more than 4.75 times as high as the pure nanotube electrode.Comparing the photoactivity of the Cu2O/TiO2 electrode obtained using sonoelectrochemical deposition with others that synthesized using plain electrochemical deposition,the photocurrent density of the former electrode was 2.2 times higher than that of the latter when biased at 1.0 V（vs.Ag/AgCl）.The reproducible photocurrent response under intermittent illumination demonstrated the excellent stability of the composite electrode.Such kind of composite electrode material will have many potential applications in solar cell and other fields.展开更多
基金sponsored by the National Key R&D Program of China(Grant Nos.2022YFC2402500 and 2022YFB3205602)the National Natural Science Foundation of China(Grant Nos.62121003,T2293730,T2293731,62333020,62171434,62471291)+2 种基金the Major Program of Scientific and Technical Innovation 2030(Grant No.2021ZD02016030)the Joint Foundation Program of the Chinese Academy of Sciences(Grant No.8091A170201)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(Grant No.PTYQ2024BJ0009).
文摘Anesthesia plays a crucial role in regulating physiological states during medical procedures,but its effects on neural activity remain incompletely understood,particularly at the prefrontal cortical level.The prefrontal cortex is essential for various cognitive and motor functions,yet high-spatiotemporal-resolution electrodes at the cellular level remain challenging to develop,which has hindered the acquisition of detailed electrophysiological data from anesthetized subjects.Here,we design a 16-channel silicon-based microelectrode array(MEA),which,after modification with platinum black nanoparticles,exhibits significantly reduced impedance(22.5 kΩ)and increased phase(−33.5°),enhancing its electrical performance and electrophysiological signal detection capabilities.Using this modified MEA,we have recorded cellular-level neural activity during the recovery process of a rhesus macaque following prolonged anesthesia.Over a 660 s period,we observed a gradual increase in the neuronal firing rate in the F7 area,along with distinctive patterns in local field potentials across different frequency bands.Notably,power in the δ and θ bands increased continuously during recovery,highlighting their potential role in the transition from anesthesia to wakefulness.Our findings provide new insights into the dynamic recovery process of cortical neurons and offer a powerful tool for high-spatiotemporal-resolution neural monitoring in nonhuman primates.
基金financially supported by the National Natural Science Foundation of China(No.51972095).
文摘The development of bifunctional electrocatalysts for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)at high current density under industrial temperatures is crucial for large-scale industrial hydrogen production from water splitting.In this work,M-MnO_(2)@TNTA composite electrodes were prepared by depositing various metal ion-doped manganese oxide nanoparticles on the titania nanotube array(TNTA)by successive ionic layer adsorption reaction(SILAR)method,and their HER and OER electrocatalytic performances were investigated in 1 M KOH.Results show that the CoFe-MnO_(2)@TNTA composite electrode prepared by simultaneous doping of Co^(3+)and Fe^(3+)in MnO_(2) exhibits optimal catalytic performance.Compared with MnO_(2)@TNTA without ion doping,the overpotentials of CoFe-MnO_(2)@TNTA at 10 mA cm^(-2)(η_(10))for HER and OER are reduced by 571 and 665 mV.In addition,the electrode perfor-mance can be significantly enhanced by increasing the test temperature,and the porous array structure enables CoFe-MnO_(2)@TNTA to exhibit better performance at high current densities.At 50℃,which is the common industrial electrolytic water temperature,the η_(10) of CoFe-MnO_(2)@TNTA for HER is almost equal to that of the Pt/C electrode.The η_(100) of CoFe-MnO_(2)@TNTA for HER is reduced by 35 mV compared with the Pt/C electrode.Moreover,η_(200) of CoFe-MnO_(2)@TNTA for OER is significantly lowered by 111 and 184 mV compared with IrO_(2) and RuO_(2) electrodes.Utilizing CoFe-MnO_(2)@TNTA as both the cathode and anode for overall water splitting,the electrolysis voltage is merely 2.33 V under the current density of 200 mA cm^(-2),much lower than that of IrO_(2)(+)||Pt/C(-)(2.68 V).The present work may provide a valuable reference for the development of self-supporting bifunctional electrodes suitable for high-current-density water splitting at industrial temperatures.
基金supported by the National Natural Science Foundation of China(General Program)under Grant 52571385National Key R&D Program of China(Grant No.2024YFC2815000 and No.2024YFB3816000)+12 种基金Open Fund of State Key Laboratory of Deep-sea Manned Vehicles(Grant No.2025SKLDMV07)Shenzhen Science and Technology Program(WDZC20231128114452001,JCYJ20240813112107010 and JCYJ20240813111910014)the Tsinghua SIGS Scientific Research Startup Fund(QD2022021C)the Dreams Foundation of Jianghuai Advance Technology Center(2023-ZM 01 Z006)the Ocean Decade International Cooperation Center(ODCC)(GHZZ3702840002024020000026)Shenzhen Key Laboratory of Advanced Technology for Marine Ecology(ZDSYS20230626091459009)Shenzhen Science and Technology Program(No.KJZD20240903100905008)the National Natural Science Foundation of China(No.22305141)Pearl River Talent Program(No.2023QN10C114)General Program of Guangdong Province(No.2025A1515011700)the Guangdong Innovative and Entrepreneurial Research Team Program(2023ZT10C040)Scientific Research Foundation from Shenzhen Finance Bureau(No.GJHZ20240218113600002)Tsinghua University(JC2023001).
文摘Developing effective,versatile,and high-precision sensing interfaces remains a crucial challenge in human-machine-environment interaction applications.Despite progress in interaction-oriented sensing skins,limitations remain in unit-level reconfiguration,multiaxial force and motion sensing,and robust operation across dynamically changing or irregular surfaces.Herein,we develop a reconfigurable omnidirectional triboelectric whisker sensor array(RO-TWSA)comprising multiple sensing units that integrate a triboelectric whisker structure(TWS)with an untethered hydro-sealing vacuum sucker(UHSVS),enabling reversibly portable deployment and omnidirectional perception across diverse surfaces.Using a simple dual-triangular electrode layout paired with MXene/silicone nanocomposite dielectric layer,the sensor unit achieves precise omnidirectional force and motion sensing with a detection threshold as low as 0.024 N and an angular resolution of 5°,while the UHSVS provides reliable and reversible multi-surface anchoring for the sensor units by involving a newly designed hydrogel combining high mechanical robustness and superior water absorption.Extensive experiments demonstrate the effectiveness of RO-TWSA across various interactive scenarios,including teleoperation,tactile diagnostics,and robotic autonomous exploration.Overall,RO-TWSA presents a versatile and high-resolution tactile interface,offering new avenues for intelligent perception and interaction in complex real-world environments.
基金National Natural Science Foundation of china(No.U2241205)the Natural Science Basic Research Program of Shaanxi(Nos.2022JC-33,2023-GHZD-35,and 2024JC-ZDXM-25)+1 种基金the Fundamental Research Funds for the Central Universitiesthe National 111 Project to provide fund for conducting experiments。
文摘In this study,the design,analysis,manufacturing,and testing of a 3D-printed conformal microstrip array antenna for high-temperature environments is presented.3D printing technology is used to fabricate a curved ceramic substrate,and laser sintering and microdroplet spraying processes are used to add the conductive metal on the curved substrate.The problems of gain loss,bandwidth reduction,and frequency shift caused by high temperatures are addressed by using a proper antenna design,with parasitic patches,slots,and metal resonant cavities.The antenna prototype is characterized by the curved substrates and the conductive metals for the power dividers,the patch,and the ground plane;its performance is examined up to a temperature of 600℃in a muffle furnace and compared with the results from the numerical analysis.The results show that the antenna can effectively function at 600℃and even higher temperatures.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.NRF-2021M3H4A1A02048529)the Ministry of Trade,Industry and Energy(MOTIE)of the Korean government under grant No.RS-2022-00155854support from the DGIST Supercomputing and Big Data Center.
文摘To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.
基金funding support from Natural Science Foundation of Shanghai(Grant No.23ZR1443900)the National Natural Science Foundation of China(Grant Nos.22178309,22476131 and 22176127)。
文摘Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.
基金The National Natural Science Foundation of China(No. 61076118, 90307013, 90707005)the Natural Science Foundation of Jiangsu Province (No. BK2008032)Special Foundation and Open Foundation of the State Key Laboratory of Bioelectronics of Southeast University
文摘A microelectrode array（MEA） is presented, which is composed of 60 independent electrodes with 59 working ones and one reference one, and they are divided into 30 pairs. Except for the reference electrode, each pair consists of one stimulating electrode and one recording electrode. Supported by the peripheral circuits, four electrode states to study the bioelectrical signal of biological tissue or slice cultured in-vitro on the surface of the electrodes can be realized through each pair of electrodes. The four electrode states are stimulation, recording, stimulation and recording simultaneously, and isolation. The state of each pair of working electrodes can be arbitrarily controlled according to actual needs. The MEAs are fabricated in printed circuit board （PCB） technology. The total area of the PCB-based MEA is 49 mm × 49 mm. The impedance measurement of MEA is carried out in 0.9% sodium chloride solution at room temperature by means of 2-point measurements with an Agilent LCR meter, and the test signal for the impedance measurement is sinusoidal （AC voltage 50 mV, sweeping frequency 20 Hz to 10 kHz）. The electrode impedance is between 200 and 3 kΩ while the frequency is between 500 and 1 000 Hz. The electrode impedance magnitude is inversely proportional to the frequency. Experiments of toad sciatic nerve in-vitro stimulation and recording and signal regeneration between isolated toad sciatic nerves are carried out on the PCB-based MEA. The results show that the MEA can be used for bioelectrical signal stimulation, recording, stimulation and recording simultaneously, and isolation of biological tissues or slices in-vitro.
基金supported by the National Natural Science Foundation of China,Nos.61534003 (to ZGW) and 61874024 (to ZGW)。
文摘Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ23E010004)the National Key Research and Development Program of China(No.2021YFB3200801)。
文摘Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose cell-electrode interface.To investigate intracellular electrophysiological signals with high sensitivity,electroporation was used to obtain intracellular recordings.In this study,a biosensing system based on a nanoporous electrode array(NPEA)integrating electrical perforation and signal acquisition was established to dynamically and sensitively record the intracellular potential of cardiomyocytes over a long period of time.Moreover,nanoporous electrodes can induce the protrusion of cell membranes and enhance cell-electrode interfacial coupling,thereby facilitating effective electroporation.Electrophysiological signals over the entire recording process can be quantitatively and segmentally analyzed according to the signal changes,which can equivalently reflect the dynamic evolution of the electroporated cardiomyocyte membrane.We believe that the low-cost and high-performance nanoporous biosensing platform suggested in this study can dynamically record intracellular action potential,evaluate cardiomyocyte electroporation,and provide a new strategy for investigating cardiology pharmacological science.
基金supported by the China Capital Health Research and Development of Special (No. 2018-14111)the National Natural Science Foundation of China (grant No. 62004007 and No. 82027805)the China Postdoctoral Science Foundation Grant (No. 2021M700258)
文摘Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications.Existing schemes are limited by flexibility,biosafety,and manufacturing costs,which create large barriers for wider applications.Here,we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface,robustness of microneedles to penetrate the skin without fracture,and a simplified process to allow mass production.The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording.The normalized electrode–skin contact impedance reaches 0.98 kΩcm^(2)at 1 kHz and 1.50 kΩcm^(2)at 10 Hz,a record low value compared to previous reports and approximately 1/250 of the standard electrodes.The morphology,biosafety,and electrical/mechanical properties are fully characterized,and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized.The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording(over 8 h per night),providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.
基金Supported by the National Natural Science Foundation of China
文摘Conducting polymers have been studied extensively. An interesting property of the conducting polymer is that the conductivity of some polymers, such as polypyrrolc, polyaniline, poly(3-methylthiophene) etc. , is affected by the voltage applied to them. For polypyrrole, the oxidized state is an electronic conductor and the reduced state is essentially insulating. Using this property, one can fabricate the polymer-based electronic devices. Experimental results of Pickun
基金supported by the National Natural Science Foundation of China(Nos.11372349,11502295,and11572349)
文摘Plasma Synthetic Jet(PSJ) actuators have shown wide and promising application prospects in high-speed flow control, due to their advantages including high exhaust speed, wide frequency band, rapid response, and non-moving components. Although previous studies on PSJ actuators are abundant, most of them have focused on the performance of a single actuator. However, in practice, an actuator array is very necessary for large-scale aerodynamic actuation on account of the small affected area of a single PSJ. In this paper, the characteristics of a twoelectrode plasma synthetic jet actuator array in serial are investigated experimentally. Compared to a parallel actuator array, the serial actuator array requires simpler power supply design and is much easier to realize. High-speed photography of the discharge evolution, voltage-current measurement, and shadowgraphy visualization are used in the investigation. Experimental results show that, for the serial actuator array, weak discharges happen firstly between energized and suspending electrodes, and then a strong pulse arc discharge is triggered. The breakdown voltage in serial is irrelevant to such factors as the number of actuators, the maximum or minimum gap in serial,the connection sequence, etc. It is mainly determined by the sum of gaps. For serial actuators with the same anode-to-cathode spacing, the energy deposition is the same, and the jet is synchronous and similar. Because of the entrainment and merging of adjacent jet vortices, the jet front speed of an aligned synchronous jet array increases as the orifice distance decreases. To achieve the highest jet front velocity, the orifice of the actuator has an optimal diameter.
文摘Objective: Determine the occurrence rate of cochlear implant (CI) electrode tip fold-over and electrode scalar deviation as reported in patient cases with different commercial electrode types. Data-sources: PubMed search for identifying peer-reviewed articles published till 2018 on CI electrode tip fold-over and scalar deviation. Key-words for searching were “Cochlear electrode tip fold-over”,“Cochlear electrode scalar position” and “Cochlear electrode scalar location”. Articles-selection: Only if electrode related issues were investigated in patient cases. 38 articles met the inclusion-criteria. Results: 13 articles on electrode tip fold-over issue covering 3177 implanted ears, out of which 50 ears were identified with electrode tip fold-over with an occurrence rate of 1.57%. Out of 50 ears, 43 were implanted with pre-curved electrodes and the remaining 7 with lateral-wall electrodes. One article reported on both tip fold-over and scalar deviation. 26 articles reported on the electrode scalar deviation covering an overall number of 2046 ears out of which, 458 were identified with electrode scalar deviation at a rate of 22.38%. After removing the studies that did not report on the number of electrodes per electrode type, it was 1324 ears implanted with pre-curved electrode and 507 ears with lateral-wall electrode. Out of 1324 pre-curved electrode implanted ears, 424 were reported with scalar deviation making an occurrence rate of 32%. Out of 507 lateral-wall electrode implanted ears, 43 were associated with scalar deviation at an occurrence rate of 6.7%. Conclusion: This literature review revealing the fact of higher rate of electrode insertion trauma associated with pre-curved electrode type irrespective of CI brand is one step closer to obsolete it from the clinical practice in the interest of patient's cochlear health.
基金supported in part by the National Natural Science Foundation of China(Grant No.62104056)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ21F010010)+4 种基金the National Natural Science Foundation of China(Grant Nos.62141409 and 62204204)the National Key R&D Program of China(Grant No.2022ZD0208602)the Zhejiang Provincial Key Research&Development Fund(Grant Nos.2019C04003 and 2021C01041)the Shanghai Sailing Program(Grant No.21YF1451000)the Key Research and Development Program of Shaanxi(Grant No.2022GY-001).
文摘Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stability have hindered their large-scale commercial application.Herein,aflexible capacitive pressure sensor based on an interdigital electrode structure with two porous microneedle arrays(MNAs)is pro-posed.The porous substrate that constitutes the MNA is a mixed product of polydimethylsiloxane and NaHCO3.Due to its porous and interdigital structure,the maximum sensitivity(0.07 kPa-1)of a porous MNA-based pressure sensor was found to be seven times higher than that of an imporous MNA pressure sensor,and it was much greater than that of aflat pressure sensor without a porous MNA structure.Finite-element analysis showed that the interdigital MNA structure can greatly increase the strain and improve the sensitivity of the sen-sor.In addition,the porous MNA-based pressure sensor was found to have good stability over 1500 loading cycles as a result of its bilayer parylene-enhanced conductive electrode structure.Most importantly,it was found that the sensor could accurately monitor the motion of afinger,wrist joint,arm,face,abdomen,eye,and Adam’s apple.Furthermore,preliminary semantic recognition was achieved by monitoring the movement of the Adam’s apple.Finally,multiple pressure sensors were integrated into a 33 array to detect a spatial pressure distribu-×tion.Compared to the sensors reported in previous works,the interdigital electrode structure presented in this work improves sensitivity and stability by modifying the electrode layer rather than the dielectric layer.
基金supported by the National Natural Science Foundation of China(21507104)Natural Science Basic Research Plan in Shaanxi Province of China(2017JM2015)~~
文摘A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.
文摘Oxygen electrocatalysis,exemplified by the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is central to energy storage and conversion technologies such as fuel cells,metal-air batteries,and water electrolysis.However,highly effective and inexpensive earth-abundant materials are sought after to replace the noble metal-based electrocatalysts currently in use.Recently,metal-organic frameworks(MOFs)and carbon-based MOF derivatives have attracted considerable attention as efficient catalysts due to their exceedingly tunable morphologies,structures,compositions,and functionalization.Here,we report two-dimensional(2D)MOF/MOF derivative coupled arrays on nickel foam as binder-free bifunctional ORR/OER catalysts with enhanced electrocatalytic activity and stability.Their remarkable electrochemical properties are primarily attributed to fully exposed active sites and facilitated charge-transfer kinetics.The coupled and hierarchical nanosheet arrays produced via our growth-pyrolysis-regrowth strategy offer promise in the development of highly active electrodes for energy-related electrochemical devices.
基金supported by the Natural Science Foundation of Hunan Province (grant no. 2018JJ2485)Hunan Provincial Science and Technology Plan Project (grant nos. 2018RS3008 and 2017TP1001)+1 种基金the National Natural Science Foundation of China (grant no. 21872174)Innovation-Driven Project of Central South University (grant nos. 2016CXS031 and 2017CX003)
文摘Direct electrochemical reduction of CO2 to multicarbon products is highly desirable, yet challenging. Here, we present a potentiostatic pulse-electrodeposition of high-aspect-ratio CuxAuy nanowire arrays (NWAs) as high-performance electrocatalysts for the CO2 reduction reaction (CO2RR). The surface electronic structure related to the Cu:Au ratio in the CuxAuy NWAs could be facilely modulated by controlling the electrodeposition potential and the as-fabricated CuxAuy NWAs could be directly used as the catalytic electrode for the CO2RR. The morphology of the high-aspect-ratio nanowire array significantly lowers the onset potential of the alcohol formation due to the diffusion-induced enhancement of the local pH and CO concentration near the nanowire surface. Besides, the properly adjusted surface electronic structure of the CuxAuy NWA enables the adsorption of CO and facilitates the subsequent CO reduction to ethanol via the C-C coupling pathway. Owing to the synergistic effect of morphology and electronic structure, the optimized CuxAuy NWA selectively reduces CO2 to ethanol at low potentials of -0.5——0.7 V vs. RHE with a highest Faradaic efficiency of 48%. This work demonstrates the feasibility to optimize the activity and selectivity of the Cu-based electrocatalysts toward multicarbon alcohols for the CO2RR via simultaneous adjustment of the electronic structure and morphology of the catalysts.
文摘Neuronal connections can be detected by neuronal network discharges in hippocampal neurons cultured on multi-electrodes.However,the multi-electrode-array（MEA）has not been widely used in hippocampal slice culture studies focused on epilepsy.The present study induced spontaneous synchronous epileptiform activity using low Mg2＋artificial cerebrospinal fluid on acute hippocampal slices to record hippocampal discharges with MEA.Results showed that burst duration and average number of spikes in a burst were significantly greater in the CA3 compared with dentate gyrus and CA1 areas.In Schaffer cut-off group,CA1 area discharges disappeared,but synchronous discharges remained in the CA3 area.Moreover,synchronous discharge frequency in the Schaffer cut-off group was similar to control.However,burst duration and average number of spikes in a burst were significantly decreased compared with control（P 〈 0.05）.Results demonstrated that highest neuronal excitability occurred in the CA3 area,and synchronous discharges induced by low Mg2＋originated from the CA3 region.
基金This work is supported by Zhejiang Provincial Natural Science Foundation of China(Grant No.LY17E040001)National Natural Science Foundation of China(Grant No.51772272,51728204)+2 种基金Fundamental Research Funds for the Central Universities(Grant No.2018QNA4011)Qianjiang Talents Plan D(QJD1602029)Startup Foundation for Hundred-Talent Program of Zhejiang University。
文摘The advancement of supe rcapacitors largely relies on the innovation of electrode materials with high-rate performance and ultra-long cycling stability.In this work,unique N-doped nanofibers on carbon cloth(NCNFs/CC) are prepared by an electrodepositio n-annealing method for application in supercapacitors.The as-prepared N-doped nanofibers(N-CNFs) show diameters of 100-150 nm and cross-link with each other fo rming porous conductive network.Due to enhanced conductivity and reinforced structural stability,the N-CNFs/CC arrays are demonstrated with better electrochemical performance than CNFs/CC counterpart,including higher specific capacitance(195.2 F g^-1 at a current density of 2.5 A g^-1),excellent rate capability(80.5.% capacity retention as the rate increases from 2.5-20 A g^-1) and good cycling stability(99.5.%retention after 10,000 cycles).These reinforced electrochemical properties are attributed to N-doped conductive architecture with faster ion/electron transfer paths and more active sites.Our findings may offe r a new way for construction of advanced high-rate electrodes for energy storage.
基金the State Key Development Program for Basic Research of China (Grant No.2009CB220004)the Shanghai Basic Research Key Project (08JC1411300,0952nm01800)+1 种基金the National High Technology Research and Development Program of China (Grant No.2009 AA063003)Shanghai Tongji Gao Tingyao Environmental Science and Technology Development Foundation for financial support
文摘Copper and titanium remain relatively plentiful in earth crust.Therefore,using them in solar energy conversion technologies are of significant interest.In this work,cuprous oxide（Cu2O）-modified short TiO2 nanotube array electrode was prepared based on the following two design ideas:first,the short titania nanotubes obtained from sonoelectrochemical anodization possess excellent charge separation and transportation properties as well as desirable mechanical stability;second,the sonoelectrochemical deposition technique favours the improvement in the combination between Cu2O and TiO2 nanotubes,and favours the dispersion of Cu2O particles.UV-Vis absorption and photo-electronchemical measurements proved that the Cu2O coating extended the visible spectrum absorption and the solar spectrum-induced photocurrent response.Under AM1.5 irradiation,the photocurrent density of the composite electrode（i.e.sonoelectrochemical deposition for 5 min） was more than 4.75 times as high as the pure nanotube electrode.Comparing the photoactivity of the Cu2O/TiO2 electrode obtained using sonoelectrochemical deposition with others that synthesized using plain electrochemical deposition,the photocurrent density of the former electrode was 2.2 times higher than that of the latter when biased at 1.0 V（vs.Ag/AgCl）.The reproducible photocurrent response under intermittent illumination demonstrated the excellent stability of the composite electrode.Such kind of composite electrode material will have many potential applications in solar cell and other fields.
